[tz] [PROPOSED] Remove old Y2K code

[Jonathan Lennox]

On Wednesday, June 14 2017, "Robert Elz" wrote to "Jonathan Lennox, Paul Eggert, Time zone mailing list" saying:

>     Date:        Tue, 13 Jun 2017 14:17:57 -0400
>     From:        Jonathan Lennox <lennox at cs.columbia.edu>
>     Message-ID:  <22848.11349.984541.13180 at compute03.cs.columbia.edu>
> 
>   | Since DEPRECATE_TWO_DIGIT_YEARS is used in an if statement, shouldn't this
>   | be -DDEPRECATE_TWO_DIGIT_YEARS=true ?  Otherwise it expands to
>   |     if ( && warn != IN_NONE ...
>   | 
>   | which obviously won't compile.
> 
> When did cpp change so that
> 	-DSTRING
> did not cause
> 	#define STRING 1
> (effectively).
> 
> Someone would need to do -DDEPRECATE_TWO_DIGIT_YEARS=
> to get the interpretation you are assuming, I believe.

Ah - perhaps I never knew that feature.

Regardless, it was surprising to me, so I'd recommend making the 'true' explicit.

-- 
Jonathan Lennox
lennox at cs.columbia.edu